Electric impulse counting chains



Nov. 1, 1955 G. J. R. PIEL 2,722,601

ELECTRIC IMPULSE COUNTING CHAINS Filed July 25, 1950 1% M KW r 7 I t sd-W11 2,721,601 i V I signals, in order that dephasing due 'to parasiticcapacities CTRI P SE N 'QHA S and intertubes liaison capacities shouldallow acqrrect Gerard Jean Rene Pie], Paris, France, assignor to SocietefflPP eper hq Input mlf P E *3?! dElectronique et dAutornatisme, Paris,France, a cor he si n tnpl he P1 e 18 Y, .pomfi n of France r a 5 dghasegi the above-mentioned oppos tion effect 1s h t f July? hln'pr'actice, this has as a result, as is well known,

- mm'spnontyalip 0 designing such binary chainsis always a quitedelicate 4 3 Claims 250-27) r operatiojrn'and that adjustments must befrequently'recti -The present invention relates to improvements in flee?fj'gd when replacing a tube, and principally, also, that the trioimpulse-counting chains constituted by-a' Casc'adear ih simply v 1 1;ag's niu st heprotected against variations rangcment of bi-stabletrigger circuits, operating-ind of the mains voltage. ybinary stages,that isfis'tages which l "Dis symmetrical input trigger.stages are alsoknown/Iii deliver, for 'each pair of actuating impulses successi" 1yone, of these the circuitof 'the tubes is keptfsymmetr'ical, pptheir'input y the preceding stage, o sew Earth; input through thecoupling capacitor acts onlylqn ing impulse to the following stage. Suchan operation e gr d of i f hil h g id fthg other b; qf a' ofa bi-stabletrigger circuit as a binary stage may, as well pai eiv no input impulse,such decoupling.being' 'duc known, he obtained through providing theactuatingor to lpb i i t I other vty e, the' so called exciting SighalWithshitahle form and p i' h y S ch'mitts, circuit, the circuitof thetubes is asymmetrical, designing its arrangement so that no inconvenientparasitic comprising only one connection between the anode of theimpedance may-appear on the electrodes, due. to the ap- W fi g' b nflhid f h d, v p U I plied signals'jbeing made use of. 2 None of thesetriggerfcircuits may be directly inserted Convehfiehal binary eehhhhgchains generally in a' binary chain, "as the'tri'gger' circuit can only,operate madeiof symmetrical bi-stable trigger circuit connected-in h i lof alternating l iti r li d to it Cascade y means of Such "connectingcircuits that i input electrode, and, consequcntly,:it would not operatecircuits eliminate impulses of one polarity issued from'the V as abinary stage, as i would remain locked in the p preceding stage andapply th impulses 0f 'theffeverse tion' to which'the precedingstagewould have brought'it Polarity-fret!1 the Same pp y alternativelytoeithehohe through 'application of vthe impulse. having the polarity0fv 1 ihpuhehahhels 0f the following Stage, according determined by'the'connection of the unidirectional con.- to an 'equivalentembodiment, to both channels inparallel. d n' element I I eIn'suchbinary counting'chains each of the cascade con- "lfo ieffibj' t f-the present invention iS-to provide a heeted stages eompfiees twoelectron tubes (Preferably binary-counting chain of'any' desired numberof bistable p Symmetrical grid Plate coupling e niigg'eristage'sconnected in cascade, which-does not have ef p y networks and commoneathedeehiae the limitations and disadvantages of binary counting chainsy means of a resistor and a y- Thev grid "b of the prior art, and todo'this by the use of dissynnnetrical Sisters are ex common, thfollgh ao p a controlitn'gger "stages which are coupled in cascade by tor. Inorder that said capacitor should only'transmit irnmeans f novel interstage coupling ir uits so'designed Pulses of one partiehlaf'pelarity,there is eenhee'tedfiih that the stages can tip or trip from onebalanced condiseries'with the anode resistance of-the tube chosen asout'- i to th whenever th i applied t theirI.inpu't P hiltefstagecoupling tube, netwol'kihlade Of all 40 electrode the fixedpredetermined-polarity impulse issuing inductance and a unilateralconductor through which'the f h e di t I I; impulses Of Onepolarityeareshort-eireuiteda The invention is illustrateddiagrammaticallyiinthe 'y' Counting ehaills; each S g mils! be singlefigureof the drawing which-shows two binary trig adapted to be operatedthrough the transformedvoltage ntage conne t d incascade, the.tworstages being step -obtained at the-preceding stage output tubeanode identical and the same elements int-the two stages being Withoutinterference due the yp f eehlleetieh representedby. the same referencenumerals, except for adopted; Said Voltage p is e011eeted"fr0m anthe-input coupling condensers in the two stages.&

electrode which-plays an active part in the trigger opera- E h e i f d fan input b v L1. nd tion. This'is well known in all symmetrical bistahle trigputputtube L2 connected as a trigger stage, the resistances rcircuits new use, and, ll higher degree in 7 inductancess, rectifiere1e'ments'9 being connected in 10 6 f Said eireuits in which thetransfer connection the: usual. manner. -':The' twoxtubes areprovidedtwith'a from-one stage to *t cr l g one is pp directly commoncathode biasing resistor 15, and tubeLZ is pro:- froms-thexoutputelectrode, be it the anode-,orzanYMhm videdwith a grid-resistor 14. Theanode-of; tube Isl-is electrode,- the undesired impulse-polarity beingthen:Si1P'- connected to the control 'grid of tube L2 by the networkPressed the Connecting Circuit and'net at the olltplltof 11 formed ofacondens'er anda parallel resistor. :Thegrid said-electrode. The resultis thatthe presence of the inter- 2 f ea h input tub L1 is connected toa potentiometer Stage Connecting Circuits, independently of theirStrlletllre, formed of resistors. 38 and139' connected between lgroundintroduces impedance dissymmetries (as regards the-stage and the. sourceof anode potential, and the input to each pp g operation) which Cannotbe C r d inc rth stage is connected to the same point on thepotentiometer input impedance of a. symmetrical trigger circuit-is inall through'a coupling condenser 30 for the first stage'and 40 casesvariable during its operation, notwithstanding the for the second stage.5 previous choice made of the input electrode. The essential feature ofthe inventioniis that when'im- Moreover, in such chains, although theinput signal first pulses of. only one polarity are'vapplied. to=theinput affects on lythe tube that is in unlocked condition 'at. the of.thefirst stage, impulses of .alternatelypositive' and instantat whichsaid signal is applied, said signal, during 5 negative. polarity areapplied to the'input tube of the flip flop operation, is always inopposition to;the.-signal second stage. I amplified through theunlocked-tube, intthe lockedj tube If tube L1 is locked or blocked, apositive'impulse apthe; condition of which is to be changed, i Iplied'to; connection -30 ,y38, causes. the ,tipping or-tripping ggltl nsq ie t y when constructing such binary chain f he.tage,-dueto'releasing-ofztube L1 andilocking iof the problernro fensuring the operational security is made tubal-21 1f; ajfurtherpositive impulse" is. thenuapplied particularly diiiicult in that itnecessitates a very precise to-s-aid connection and if,-.following'thepreceding-tipping; choice 0f tube gains and a well defined formnof'input tubebl, released, isbiased to zero grid. potential, .due to thesmall impedance of the input grid circuit, capacitor 30 is being chargedto the crest voltage of said-further impulse, so that, during the returntime 'of the impulse the grid potential of tube L1 sinks till it bringssaid tube L1 to the point at which its plate current begins to flow (theso called "cut-off" point of the tube) and causes the desired tipping.Accordingly, for the back-stroke front of the impulse, the gridimpedance of tube L1 has become of a practically equal value to that ofresistor 38 and the grid-leak potential variation then follows the shapeof said front. 1

The time constant R. C. of the input connection is, of course, chosen ofa value less than to the minimum interval separating two consecutiveinput impulses, so that capacitor 30 may be discharged during said timeinterval and that the system should accordingly recover its restcondition during said time interval. I The stability or security ofbinary counting chains according to the present invention will berendered evident by referring further to the second-stage controlledfrom the first stage through condenser 40.

Considering in said diagram the released tube L2 and the locked tube L1,if E designates the high voltage potential and if it is further assumedthat values R11 and R14 of resistors 11 and 14 are high with referenceto resistor R7 of the input tube L1, the voltage on input grid of tubeL2 has the following value is definitely below cut-01f, the system willbe stable in this condition, even with large variations of B, becausepotential Ve, like potential V, follows said variations; If potential Vis higher than the voltage drop across Ris, tube L2 remains at zero gridpotential for large variations of high voltage E, because a grid currentwill flow through resistor Rn. Such a dimensioning will be realised inpractical applications of binary chains according to the invention.

On the other hand, due to loading resistor R1 of tube L1, current T0 ofsaid tube, when its grid is at zero potential, delivers .a cathodevoltage RmTo which is ter than V0 and consistent with the unlocking oftube L1. Voltage drop R'nTo may in all cases be so great as to provide agrid potential of tube L2 which completely locks or blocks said tube.With regard to this, it may be advantageous, when designing the circuit,to maintain a grid current through resistor 39 when tube L1. isreleased, to make sure that said tube remains at hero grid potential inspite of large high voltage variations, which is a condition requiredfofjzhe operation described. Coupling capacitor 30 or 40' must bepossibly charged up to the peak value of the input impulse when tube L1is released.

The large current variation in tube L2 provides a large amplitude at theoutput of unidirectional conductive memher 9. Now, to actuate such abi-stable stage, it is sutlieient to provide an input impulse amplitudehigher than the voltage value for which both tubes L1 and L2 aresimultaneously in conductive condition, such a condition being obtainedthrough the relative dimensioning of resistors 7 and 15. Such a circuitis accordingly quite stable, with regard to signalsv available at theprovided connections.

What I claim is: v v

1. An electric impulse counting chain comprising a plurality ofcascade-connected bistable' ltr gg r circuits in dividually operating asbinary stagesf each of said stages including an unsymmetrical inputcircuit and an output circuit, means incorporated in said'output circuitto suppress impulses of a predetermined polarity whilst transmittingimpulses of the reverse polarity to the following stage, and interstagecoupling means for delivering, when actuated by an impulse of theunsuppressed pt larity, to the unsymmetrical input circuit of thefollowing stage, two consecutive voltage pulses of opposite polarities,spaced by a' period of time less than thetime period necessary for saidstage to tip over, said interstage coupling means including a capacitorconnected "in series between the output of one stage and the input ofthe following stage and a potentiometric resistor arrangementcooperating with said capacitor and the actuation input circuit of thesaid following stage, in such manner that said potentiometric resistorarrangement constitutes a self-biasing network for the said followingstage.

2. An electric impulse counting chain comprising a plurality ofcascade-connected bistable trigger circuits individually operating asbinary stages, each of the stages in said cascade comprising an inputvalvewith a grid and a ground, an unsymmetrical actuation input circuitand an output circuit, means incorporatedflin said output circuit tosuppress impulses of a predetermined polarity whilsttransmittingimpulses of the reverse polarity to the following stage, andinterstage coupling means for delivering, when actuated by an impulse ofthe unsuppressed polarity, to the unsymmetrical input circuit of thefollowing stage, two consecutive voltage pulses of opposite polarities,spaced ,by a period of time less than the time period necessary for saidtrigger stage to tip over, said inter.- stage coupling means including acapacitor connected in series between the output of one stage and theinput of the following stage and a potentiometric resistorarrangementconnectedbetween the grid of the said input valve of said stage and thesaid ground and cooperating with said capacitor and the actuation inputcircuit of the following stage, in such a' way that said potentiometricresistor tar rangement constitutes a self-biasing network for the saidfollowing stage. J

3. An electric impulse counting chain comprising a. plurality ofcascade-connected bistable trigger circuits individually operating asbinary stages, each of the stages in said cascadezcomprising an inputtube with a grid an unsymmetrical actuation input circuit and'an outputcircuit, means incorporated in said output circuit to any press impulsesof a predetermined polarity whilst trans! mitting impulses of thereverse polarity to the following stage, and interstage coupling meansfor delivering, when actuated by an impulse of the unsuppressedpolarity, to the unsymmetrical input circuit of the following stage, twoconsecutive voltage pulses of opposite polarities, spaced by a period oftime less than the time period necessary for said stage to tip over, ahigh voltage supply and a ground, said interstage couplingmeansincludinga capacitor connected in series between the output ofone stageand the input of the following stage and a potentiometric resistorarrangement connected betweenthe high voltage supply and said groundcooperating with said capacitor and the actuation input circuit of thesaid following stage in such a way that said potentiometric resistorarrangement constitutes a self-biasing network for the said followingstage, an intermediate tapon said potentiometric arrangement, and aconnection from said tap to the grid of the input tube of said followingstage.

"References Cited in the file of thispatent UNITED STATES PATENTS2,252,599- L eWiS Aug. 12; 1 941 2,402,917 Miller June 25, 19462,424,481 MCCOY July 22, 1947 2,426,205 Grieg et al Aug. 26, 19472,470,028 Gordon 10,194 2,478,683 1 131155 -s a-- Aug. 9, 19.492,515,195 5 Clark July '18, 1950 2,536,808 'Higinbotham Ian. 2, 19512,589,240 Frye Mar. 18, 1952

